Numbers k such that the number of steps to reach 1 in '3x+1' problem equals tau(k), the number of divisors of k.

A070980

Numbers k such that the number of steps to reach 1 in '3x+1' problem equals tau(k), the number of divisors of k.

Terms

    a(0) =40a(1) =42a(2) =96a(3) =180a(4) =280a(5) =1664a(6) =1704a(7) =1932a(8) =1960a(9) =2184a(10) =2304a(11) =2310a(12) =4816a(13) =4928a(14) =7252a(15) =9360a(16) =9792a(17) =12888a(18) =12896a(19) =13338a(20) =13720a(21) =14256a(22) =15792a(23) =16240a(24) =17408a(25) =17940a(26) =17952a(27) =18096a(28) =20000a(29) =20016

External references